The present invention relates to devices that mix two or more ingredients, for instance; liquids, granules, and their combinations, when preparing dough, cremes, and concrete.
There is an attachment known that includes two upright shafts set at some distance from each other and carrying one blade each, a blade on one shaft having its bottom element pretwisted clockwise, with respect to the top element, by 90 degrees about the shaft axis, and the blade on the other shaft, by 90 degrees counter-clockwise. With this, the side elements of the blades are helical lines, both top and bottom elements are straight line segments of equal lengths. Said shafts rotate synchronously, in mutually opposite directions (see Japanese patent #1(64)-75029, BOIF 15/02, published Mar. 20, 1989).
This design cannot reach high mixing efficiency. At high rotation speeds of 5000 to 8000 RPM (typical of state-of the-art mixers) its performance turns out to be poor.
The other prototype (Japanese patent # 62-19216, BOIF 7/18, published Apr. 27, 1987 # 2-481) includes two vertical shafts installed at a certain distance from one another, each carrying two thin-wire blades mounted normal to each other. Leading edges of side elements of the blades are sharpened. Said shafts with said blades are rotated synchronously, one clockwise and the other counter-clockwise.
This attachment does not attain high efficiency of mixing, and instead requires much energy and time in operation.